A machine-to-machine (Machine to Machine, M2M for short) communications technology is widely applied to various industries in the society. It combines a communications technology and a network technology and forms a network by connecting machinery equipment distributed throughout people's daily life, thereby improving an intelligent level of devices, and bringing a new round of reform to daily life, industrial production, and the like. The M2M communications technology has features such as a wide coverage area, no need of cabling, and the like. A mobile network technology is a most popular and most market-promising technology for carrying and transmitting information of the M2M communications technology. As bandwidth of a mobile communications network continuously increases and a data service capability increasingly improves, development of the M2M communications technology may further accelerate.
In a network architecture based on the M2M communications technology, a Machine Type Communications-Inter Working Function (Machine Type Communications-Inter Working Function, MTC-IWF for short) device may provide an MTC service or a value-added service of a service capability server (Services Capability Server, SCS for short) for a user equipment (User Equipment, UE for short), or the MTC-IWF device provides, by using a Short Message Service-Service Center (Short Message Service-Service Center, SMS-SC for short), the MTC service or the value-added service of the SCS to the UE in a form of a short message service message. When the SCS needs to exchange data with the UE but has not acquired an Internet Protocol (Internet Protocol, IP for short) address yet, the MTC-IWF device usually sends a trigger (Trigger) message to the UE according to an existing identifier of the UE, so that the UE can make a communication connection to the MTC-IWF device and exchange data with the MTC-IWF device.
An MTC-IWF device sends a trigger message to a UE in two manners: (1) The MTC-IWF device sends the trigger message to a core network, and the core network sends the trigger message to the UE; (2) The MTC-IWF device sends the trigger message to the SMS-SC, the SMS-SC sends the trigger message to the core network in a form of a short message service message, and the core network sends the trigger message in the form of a short messageservice message to the UE. In the foregoing two manners of sending the trigger message, when the MTC-IWF device or the SMS-SC fails to send the trigger message, the MTC-IWF device or the SMS-SC saves the trigger message that fails to be sent and subsequently resends the trigger message that fails to be sent. Generally, the MTC-IWF device may choose one of the foregoing two sending manners to send the trigger message, and when the trigger message fails to be sent, the MTC-IWF device chooses another sending manner to resend the trigger message.
In the foregoing process of sending the trigger message, if the MTC-IWF device chooses one sending manner to send the trigger message but fails, the MTC-IWF device chooses another sending manner to send the trigger message. However, meanwhile, a device that uses the first sending manner resends the trigger message after a time interval. For example, an MTC-IWF device chooses to send a trigger message to a UE first by using an SMS-SC, the SMS-SC fails to send the trigger message, and then, the MTC-IWF device chooses to send the trigger message to the UE by using a core network; however, meanwhile, after a period of time after failing to send the trigger message, the SMS-SC resends the trigger message to the UE, which causes a problem that the MTC-IWF device and the SMS-SC repeatedly send a same trigger message to the UE, thereby causing an unnecessary signaling overhead, and wasting network resources. Likewise, when the MTC-IWF device chooses to send the trigger message first by using the core network, a similar problem of repeatedly sending a same trigger message also exists.